A trullo (plural, trulli) is a traditionalApulian dry stone hut with a conical roof. Their style of construction is specific to the Itria Valley, in the Murge area of the Italian region of Apulia. Trulli were generally constructed as temporary field shelters and storehouses or as permanent dwellings by small proprietors or agricultural labourers. Their golden age was the 19th century.
In most countries a roof protects primarily against rain. In Persia the citizens used their roofs for milling wheat, farming, gardens and extra space. Depending upon the nature of the building, the roof may also protect against heat, sunlight, cold, snow and wind. Other types of structure, for example, a garden conservatory, might use roofing that protects against cold, wind and rain but admits light. A verandah may be roofed with material that protects against sunlight but admits the other elements.
The characteristics of a roof are dependent upon the purpose of the building that it covers, the available roofing materials and the local traditions of construction and wider concepts of architectural design and practice and may also be governed by local or national legislation.